$3.7 billion spent on transfers in 2013

As football's January transfer window prepares to shut on Friday, clubs, players and agents are involved in a complicated game of roulette -- just who will blink first?

For clubs, be they at the top or the bottom of the table, the window offers a final chance to either push them forward to title success or European Champions League qualification, or potentially rescue their top-flight status.

There is an awful lot of money at stake as well as league position.

In 2013, world governing body FIFA's Transfer Matching System handled 12,309 international player moves -- an increase of 4% on 2012 -- which were worth $3.7 billion, up a whopping 41%.

Thanks to a bumper television deal worth $4.7 billion that is shared between the 20 Premier League clubs, England spent more than any other country on transfers in 2013 -- $913 million -- an increase of 51% over the previous year.

That $913 million represents 25% of the global transfer spend.

In the current 2013-2014 season English Premier League clubs have already spent over $1.3 billion on players, more than double the sum teams in Spain, Italy and France are investing in strengthening their squads, according to the authoritative Transfermarkt website.

"Intermediaries"

Traditionally January is viewed as a bad time to invest in players, given selling clubs always demand a premium.

But that hasn't stopped champions Manchester United, struggling to qualify for next season's Champions League, signing Spain international Juan Mata for a club record $61 million from Chelsea.

While English clubs spent lavishly, Brazil once again had the most number of transfers -- 1,402 -- for both incoming and outgoing players, testament to the 2014 World Cup host's knack for developing players.

Often key to any transfer deal is the role played by what FIFA terms "intermediaries," be they agents, lawyers or even parents.

Last week Spanish club Barcelona revealed the deal to sign Brazil international Neymar cost $118 million, including a $66 million "compensation fee" paid to a company owned by the player's parents.

According to FIFA, although there was an increase of 30% in club intermediary commissions paid in 2013, there was a decrease in the actual number of transfers involving such "middle men" -- only 14% compared to 17% in 2012.

Last year's biggest transfer was Real Madrid's purchase of Wales international Gareth Bale from English club Tottenham.

The BBC reported it was a world-record move worth $132 million that was greater than the $124 million fee Real Madrid produced to lure Cristiano Ronaldo away from Manchester United in 2009.